Viaduct closure countdown: New videos show you how to navigate SR-99 tunnel

SEATTLE -- Commuters in the Puget Sound region are in for major changes starting Jan. 11, when the Alaskan Way Viaduct in Seattle closes permanently to make way for the two-mile SR-99 tunnel that will open in early February.

The three weeks between the viaduct's closure and the opening of the SR-99 tunnel under downtown are expected to cause major headaches for areas that are already prone to traffic nightmares. It's the longest highway closure ever in the Puget Sound region, and disruptions are expected for up to six weeks -- even after the tunnel opens.

City and county leaders have come up with a list of suggestions to cope with the weeks-long closure known as the "Seattle Squeeze," including adjusting your start and finish times at the office, carpooling with coworkers, using public transit -- and using personal vacation time so you can stay off the roads.

Once the tunnel opens, drivers who are accustomed to the exits on the Viaduct will have to get used to fewer entrances and exits in the downtown area.

The tunnel's entrances and exits will be located near the Space Needle on the north end and near CenturyLink Field and T-Mobile Park on the south end. After the new tunnel opens, it will take up to two weeks to complete a new northbound off-ramp into downtown Seattle – creating more traffic disruptions.

Here's a timeline of significant dates to remember for the closure:

At 10 p.m. Friday, Jan. 4, the SR 99 on-and-off-ramps close near the stadiums. An estimated 23,000 vehicles use those ramps every day.

At 10 p.m. Friday, Jan. 11, the Alaskan Way Viaduct closes between South Spokane Street and the south end of the Battery Street Tunnel. An estimated 90,000 vehicles use the viaduct every day.

Jan. 11 to early February: Three weeks of intensive construction work to realign 99 into the new SR 99 tunnel. During this time, both the viaduct and the tunnel will be closed.

The Washington Department of Transportation has released four new videos that show commuters how to navigate the new tunnel.

Driving north to and through Seattle on the new SR-99 tunnel:

Driving south to and through Seattle on the SR-99 tunnel:

Getting to northbound 99 from in and around Seattle with the new tunnel:

Getting to southbound 99 from in and around Seattle with the new tunnel: